Total Friction Management Benefits Transit Module
Goals and Objectives Why are there benefits to TFM? What is the value of TFM? Where has TFM been explored? 2
Why Control Friction? Uncontrolled friction at the wheel/rail interface results in or contributes to: } Curve noise } Excessive wheel and rail wear } Corrugations and rolling contact fatigue (RCF) } Wheel flats, SPADS (lubricant on the rail head) } Higher fuel/energy consumption } Potential safety issues: wheel climb derailment, high lateral forces (L/V) 3
TOR Friction Control and Gauge Face Lubrication Fundamental differences in the technologies involved, frictional targets, objectives and benefits. The two technologies are complementary when implemented effectively. 4
Flange/Gauge Face Lubrication Rail/Wheel Wear is the primary issue Gauge face lubrication widely implemented in the world Impacts: } Flange Noise } Rail / Wheel Wear (Gage Face, Flange) } Derailment Potential (Wheel Climb) } Rolling Contact Fatigue Development } Fuel Efficiency µ=0.1-0.2 5 High Rail Rail
Top of Rail (TOR) Friction Control Impacts: } Squeal Noise } Flange Noise (indirect) } Corrugations } Hunting } RCF Development } Rail / Wheel Wear (TOR, Tread) } Lateral Forces } Fuel Efficiency } Derailment Potential (L/V, rail rollover) µ=0.3-0.35 High Rail TOR: µ=0.3-0.35 Low Rail Coefficient of friction level does not impact braking and traction Portec Rail Products, Inc. 2010
Corrugations
Corrugation formation: common threads Traction, Friction, etc. Initial Profile Perturbation + Damage Mechanism (Wear) Wavelength Fixing Mechanism Corrugations Profile Change Under saturated lateral or longitudinal creepage, negative friction characteristic can result in self-sustained roll slip oscillations Roll slip oscillations precede and can initiate the development of corrugations Kelsan Europe Technical Conference 8
Influence of Friction Levels on Corrugation: Theory Reduced absolute friction levels on the rail head (without compromising traction / braking) expected to reduce wear component of corrugation mechanism Positive friction characteristics of interfacial layer Reduction of roll-slip oscillations associated with wavelength fixing / initiation component of corrugation mechanism 9
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TRANSIT CORRUGATION CASE STUDIES
Case Study 1: European Commuter Rail System Baseline corrugation one month after grinding 12
Case Study 1: European Commuter Rail Results 0.5 Rail Grinding and Baseline Rail Grinding and friction modifier 0.4 Amplitude (mm) 0.3 0.2 0.1 0 25-Nov-03 4-Mar-04 12-Jun-04 20-Sep-04 29-Dec-04 8-Apr-05 17-Jul-05 Measurement Date Zone 4 Zone 5 Zone 4: 200 m from start of curve start, Zone 5: 430 m from start of curve 13
Case Study 1: European Commuter Rail with Friction Modifier after Eight Months 14
Summary of Corrugation Results with KELTRACK 1.40 Review of Corrugation Results with KELTRACK Trackside Transit Application Corrugation Amplitude Growth Rate (mm/year) 1.20 1.00 0.80 0.60 0.40 0.20 0.00 Heathrow Express Metro Bilbao- Aiboa Metro Bilbao- Algorta European Metro European Metro European Metro European European Commuter Rail Commuter Rail Japanese Metro Japanese Metro Baseline KELTRACK 15
HPF Program on MTRC TKL (100% underground) Noise ( noisy saloon ) mitigation through reduced corrugation growth Extended grinding interval from 3-4 months to 6-9 months TKL Train TKL 18.8% TRAIN LCF Coverage 18.8% 31.2% LCF Effective Coverage HPF Coverage 15.6% HPF Coverage - (31.2 % Effective) 1 AXLES 2 3 4 1 AXLES 2 3 4 1 AXLES 2 3 4 1 AXLES 2 3 4 1 AXLES 2 3 4 1 AXLES AXLES AXLES 2 3 4 1 2 3 4 1 2 3 4 MOTOR MOTOR TRAILER MOTOR MOTOR TRAILER MOTOR MOTOR DENOTES LCF APPLICATION POSITION DENOTES HPF APPLICATION POSITION 16
Wheel/Rail Interface Noise
Noise Railway noise types and frequency ranges Curve noise types and frequency ranges Squeal noise generation physical mechanism and effects of KELTRACK KELTRACK noise mitigation examples / data 18
Spectral range for different noise types Noise type Frequency range, Hz Rolling 30-2500 Rumble (including corrugations) Flat spots 200-1000 50-250 (speed dependent) Ground Vibrations 30-200 Top of rail squeal 1000-5000 Flanging noise 5000 10000 19
Curve noise control with TOR friction modifiers Top of rail wheel squeal noise High pitched, tonal squeal (predominantly 1000 5000 Hz) Prevalent noise mechanism in problem curves, usually < 300m radius Related to both negative friction characteristics of Third Body at tread / top of rail interface and absolute friction level Ø Stick-slip oscillations Flanging noise Typically a buzzing OR hissing sound, characterized by broadband high frequency components (>5000 Hz) Affected by: A. Lateral forces: related to friction on the top of the low rail B. Flanging forces: related to friction on top of low and high rails C. Friction at the flange / gauge face interface 20 8 th Course on Vehicle / Track Interaction
TRANSIT NOISE CASE STUDIES
Case Study: Sacramento RTD Typical articulated LRVs 115 lb imbedded and worn rail 25m radius curve, length 76 m Significant noise complaints from local residents. Prior to installation of trackside unit, noise controlled by manual application of friction modifier 22
Average sound pressure versus frequency Sacramento RTD 90.0 Average Sound Pressure, db 70.0 50.0 30.0 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 Frequency, Hz Baseline FM Manual FM Trackside 23
Case Study: PAT Washington Junction installation Site details: Curve 1: 113 m radius, 125m length Tangent 48 m Curve 2: 113 m radius, 31 m length Initially 0.3% downgrade, then 4.1% downgrade in curves 115lb RE rail 24
Untreated Track 25
KELTRACK Treated Track
Curve Noise Reduction with Friction Modifier on Different Systems 120 100 Baseline Friction modifier LAeq, dba 80 60 40 20 0 Tram 1A Tram 1B Tram 2 Metro 3 Metro 4 Freight 5 Freight 6 27
Rail Wear 28
Rail Wear Types Wear Types } Adhesion } Oxidative } Surface Fatigue } Abrasion } Corrosion } Rolling Contact Fatigue } Plastic Flow 29
Adhesive wear rail gauge face/wheel flange interface Archard Wear Law applies to rail gauge face / wheel flange wear } Volume of wear is proportional to wear coefficient, which is also proportional to CoF V = k Ns H k proportional to COF N V = volume of wear N = normal load s = sliding distance (i.e. creepage) H = hardness k = wear coefficient s 30
Gauge Face Wear 31
Oxidative wear top of rail / wheel tread interface High stress, low frequency top-of-rail/wheel-tread contact Reaction of surface iron with oxygen Brittle oxide layer Relative motion separates layer from surface and generates wear particles Wear particles consist of compressed iron oxide and other particles 32
Dry Wheel / Rail Interface Relative Motion (Accumulating Creepage) Body 1 (Wheel) 1 2 3 4 Transition 3 RD Body Interface Transition (not to scale) Rolling Direction adh slip Relative Wheel/Rail Motion (Creepage) Accommodated by: Brittle High Hardness Wear Particles (Fe 3 O 4 ) Body 2 (Rail) DRY Wheel / Rail 1. Rolling 2. Elasticity 3. Breaking 4. Void Collapse Friction Force 1 4 Creepage July 7 th -10 th, 2008 33
KELTRACK Treated Wheel / Rail Interface Reduced wear particle generation Relative Motion (Accumulating Creepage) Body 1 (Wheel) Transition 3 RD Body Interface Transition (not to scale) Pliable Soft FM Particles Brittle High Hardness Wear Particles (Fe 3 O 4 ) Body 2 (Rail) KELTRACK creates a composite deformation mechanism Pliable FM particles provide an elastic shear displacement accommodation mechanism that negates/arrests brittle particle breaking and void collapse Friction Force DRY Wheel / Rail KELTRACK Conditioned Creepage 34
TRANSIT RAIL WEAR CASE STUDIES 35
Rail Wear: Case Study #1 14.42 Annual MGT (local regional, long distance and freight) Rail size: 60 UNI Curve Length: 1.100 m Curve Radius: 425-495 m Baseline assessment captured higher gage corner wear rates in Summer compared to Spring Seasonal effects accounted for in rail wear analysis No traffic changes were confirmed for the trial period 36
Summer Comparison: KELTRACK high rail gage corner wear rates are significantly lower than baseline 37
Rail Wear: Case Study #2 Rolling Stock } Siemens Transportation System SD400 double-ended articulated six axle LRV } One to two car configurations } 10 minute non-peak and 5 minute peak headways } Annual tonnage is approximately 11.6 MGT 38
Case Study #2: Test Site A Curve radius: 91 meters Curve length: 122 meters Gradient: 2% to 3% downhill Track gage: 1,594 mm 115 lb RE rail Strap guard on both high and low rails 39
Test Site A: Reduced High Rail Wear Rates Ave. Wear Per MGT [m 0.100 0.092 0.090 0.083 0.080 0.070 0.060 0.050 0.040 0.036 0.036 0.030 0.025 0.023 0.020 0.010 0.000 Head Wear (W1) Gauge Wear (W2) Gauge Corner Wear (W3) Baseline Average Wear Rate [MGT/Year] KELTRACK Average Wear Rate [MGT/Year] 40
Case Study 2: Test Site B Curve 1 radius: 25 meters Curve 2 radius: 119 meter 115lb RE rail Strap guard on both low and high rails Trackside Applicator Location Direction of Traffic 41
Test Site B: Reduced Low Rail Wear Rates Ave. Wear Per MGT [m 0.030 0.025 0.023 0.020 0.020 0.016 0.015 0.010 0.005 0.026 0.015 0.000 0.000 Head Wear (W1) Gauge Wear (W2) Gauge Corner Wear (W3) Baseline Average Wear Rate [MGT/Year] KELTRACK Average Wear Rate [MGT/Year] 42
Test Site B: Reduced High Rail Wear Rates 0.060 Ave. Wear Per MGT [m 0.050 0.040 0.030 0.020 0.010 0.032 0.032 0.049 0.018 0.048 0.023 0.000 Head Wear (W1) Gauge Wear (W2) Gauge Corner Wear (W3) Baseline Average Wear Rate [MGT/Year] KELTRACK Average Wear Rate [MGT/Year] 43
Wheel Wear Mitigation with Flange Lubrication and Tread Friction Control
Solid Stick Systems - Theory and Applications Overview: Wheel wear rates Case Studies High speed Metro system
Wheel Flange Wear Rates Typical Wheel Flange Wear Rates 0.14 Flange Wear Rates (M=Metro, F=Freight, H=High Speed Trains) Wear Rate (mm/kkm) 0.12 0.10 0.08 0.06 0.04 0.02 Control LCF Solid Stick 0.00 M1 M2 M3 M4 M5 M6 M7 F1 F2 F3 M7 M8 M9 H1 H2 High Speed Metros Freight Test Vehicles 0.004 0.006 0.003 0.018 0.009 0.024
Wheel Tread Wear Rates Tread wear results for an Asian metro system Average Tread Wear Rates, Baseline vs. HPF 0.025 0.022 Tread Wear (mm/kkm) 0.020 0.015 0.010 0.005 0.015 0.007 0.008 0.000 Side A Side B Baseline HPF
Case Study Case Study High Speed (KTX)
KTX System Information Commissioned 2004 Services: Between Seoul and Busan Between Seoul and Mokpo For both services, combination of both high speed and conventional track High Speed and Conventional Lines for each Service
KTX System Information High Speed Sections: Gwangmyeong to Daejeon Junction (133.1 km) Daejeon to East Daegu (133.3 km)
KTX System Information Trains travel bi-directionally Track and Rail Information All trains used on both services No trains are specifically used on the conventional or high speed lines Max. speed on high speed lines: 300 km/hr Max. speed on conventional lines: 140 km/hr
KTX Train sets Alstom design Similar to TGVs at Eurostar Up to 300 km/hr
KTX Train sets LOCOMOTIVE POWERED COACH CAR 1 CAR 2 CAR 3 CAR 4 CAR 5 CAR 6 CAR7 1 2 3 4 5 LB LB MB TB CAR 8 6 7 8 CAR 9 9 10 CAR 10 11 12 CAR 11 13 14 CAR 12 15 16 CAR 13 17 18 19 20 21 22 23 24 25 26 27 28 29 CAR 14 CAR 15 CAR 16 CAR 17 CAR 18 CAR 19 CAR 20 30 31 32 46 Train sets 33 34 35 36 23 bogies (6 powered, 17 trailer) per train 3 bogie designs Locomotive bogie (LB) Motorized bogie (MB) Trailer bogie (TB) 37 38 39 40 41 42 43 44 45 46 TB MB LB LB POWERED COACH LOCOMOTIVE
LCF Bracket and Applicator Designs Trailer Bogie Bracket Kelsan design but manufactured in Korea Similar to Eurostar design
LCF Bracket and Applicator Designs Locomotive Bogie Bracket Alstom design
LCF Bracket and Applicator Designs Motorized Bogie Bracket Alstom design Axle box mounted
LCF Configuration CAR 1 CAR 2 CAR 3 CAR 4 CAR 5 CAR 6 CAR7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 CAR 8 CAR 9 CAR 10 CAR 11 CAR 12 CAR 13 18 19 20 21 22 23 24 25 26 27 28 29 CAR 14 CAR 15 CAR 16 CAR 17 CAR 18 CAR 19 CAR 20 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 DENOTES LCF APPLICATION LOCATION DENOTES OIL APPLICATION LOCATION EKR Configuration 30% wheel coverage 2 configurations developed with input from Kelsan Eukorail (EKR) configuration - 10 trains Korean Railroad Research Institute (KRRI) configuration - 36 trains
Wheel Monitoring Test Trains Monitored Korail selected 4 trains for monitoring On board oil spray system on Train #32 was taken offline All other trains in fleet operates on both oil and LCF
Trial Results 0.010 Overall Wear Rates Flange (Sd) Tread (Sh) Gradient (qr) Flange (W) 0.008 Wear Rate (mm/kkm) 0.006 0.004 0.002 0.0020 0.0061 0.0019 0.0037 0.000 Very low flange wear rate W measurement more conservative than Sd Tread wear rate not high but almost twice that of flange wear
Trial Results Flange Wear Rate (W) 0.010 Period 1 Period 2 Period 3 Flange Wear W (mm/kkm) 0.008 0.006 0.004 0.002 0.0040 0.0057 0.0026 0.0060 0.0046 0.0037 0.0041 0.0040 0.0025 0.0034 0.0034 0.0030 0.000 KTX 3 KTX 6 KTX 13 KTX 32 Flange wear (W) rate over the 3 periods
Case Study Case Study Metro System (Suburban)
Case Study Metro (Suburban) Kuala Lumpur Airport Express with moderate curvature Commissioning tests indicated excessive flange wear and projected wheel life of 170,000 km (4.5 months operation)!
Case Study Metro (Suburban) Short term action: Manual greasing of tightest curves increased projected wheel life to 290,000 km. High labour costs. Misapplication of grease to railhead causing skid flats. Decision to implement train mounted solid sticks on fleet as a permanent solution.
Flange Wear Case Study (Suburban) 1 2 3 4 5 6 7 8 9 10 DENOTES LCF APPLICATION POSITION DENOTES ADDITIONAL LCF APPLICATOR POSITION Fleet was initially outfitted at 30% coverage with manual lubrication stopped
Case Study Metro (Suburban) 3000 2500 2430 Wheel Life (kkm) 2000 1500 1000 1700 500 170 290 0 Control Manual Greasing LCF - 30% LCF - 45% Wheel flange life extended by 10x at 30% coverage. Wheel flange life extended further at 45% coverage. Increased train availability. Reduction in rail wear extending life of track. Environmental cleanliness, both track and train. Net savings >US$ 2,000,000 in wheel related costs.
LCF Film Transfer Mechanism The solid stick lubricant is applied directly to the wheel flange of a rail vehicle The LCF material transfers to the wheel flange and in turn to the gauge face of the rail A thin film is left behind on the gauge face of the rail that provides superior lubrication to the wheel/rail interface throughout the railway system. Film Transfer to Rail Film Transfer to Other Wheels
Rail Wear Reduction also Achieved with LCF Implementation Bombardier, Ankara Turkey Rail Wear Study: Excessive rail gauge corner wear 9 months after the transit system opened. No track lubrication other than hand application of grease to mainline switches and some yard check rails. Initial reduction of wear rates with hand application of liquid LCF. Initiated on-board LCF stick application (25% wheel coverage) and detailed Miniprof rail wear measurements.
Rail Wear Reduction also Achieved with LCF Implementation Bombardier, Ankara Turkey 200 500% increase in Rail Gauge Life 0.3 Side Rail Wear rate, mm / month 0.25 0.2 0.15 0.1 0.05 Unlubricated Kelsan LCF 0 1 2 3 4 Curve locations
Rolling Contact Fatigue 69
RCF Development: Shakedown Increased Mat l Strength Reduced Stress (e.g. wheel/rail profiles) Reduced Traction Coefficient (e.g. reduced friction) 70
Wheel / Rail Test Stand Results*: Reduced Wear and RCF New 60E1 FM Applied / 250 Cycles Dry Rail * Collaborative project with voestalpine Schienen GmbH, published at CM2006 (Brisbane) 71
Lateral Forces 72
Saturated Creepage Conditions Under saturated creepage conditions, low rail and high rail lateral forces primarily related to the coefficient of friction on the low rail Wheelbase, 2L V Curve Radius, R α Angle of Attack, α Low rail lateral force = Low rail CoF x Vertical force High rail lateral force = Low rail CoF x Vertical force + some contribution from longitudinal forces 73
Lateral Force Reductions in Sharp Curves Direction of Travel Direction of Travel AoA Flange Force Contact Patch Track Spreading Forces Lateral Longitudinal Spin Creepage Creepage Creepage Friction Forces (Lateral Creepage from AoA) Reduced TOR friction Anti-Steering Moment (Longitudinal Creepage from mismatched rolling radii) September 12 th -14 th, 2006 74 8 th Course on Vehicle / Track Interaction
Impacts of High Lateral Loads Wheel Climb Derailments Both GF Lubrication and TOR Friction Control have a beneficial impact. Lateral/Vertical Force 3.5 3 2.5 2 1.5 1 0.5 0 55 60 65 70 75 80 85 Flange Angle (Degrees) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 75
Impacts of High Lateral Loads Fastener Fatigue / Clip Breakage Transit example: 76
Clip Breakage Dramatically Reduced Number of Broken Clips recorded (normalized to traffic frequency) 50 40 30 20 10 Phase 1 Installation Baseline peak clip breakage breakage Baseline avg. clip breakage Grinding Terminal 4 - CTA Change in service: Class 332 to 360 Phase 2 Installation Phase 1 Mods Phase 2 Mods Grinding 8225 points - CTA 0 18-Mar-09 17-Jan-09 18-Nov-08 19-Sep-08 21-Jul-08 22-May-08 23-Mar-08 23-Jan-08 24-Nov-07 25-Sep-07 27-Jul-07 28-May-07 29-Mar-07 28-Jan-07 29-Nov-06 30-Sep-06 1-Aug-06 Date 77
Lateral Force Reduction with KELTRACK 30% Frequency 20% 10% 0% 0.0 0.1 0.2 0.3 0.4 0.5 0.6 L/V Ratio Baseline KELTRACK 0.2sec KELTRACK 0.3sec 78
Case Studies (Trackside Application of ALLEVIATE ) 79 79
What is ALLEVIATE? Water-based suspension of dry solids, no oil or grease components (environmentally benign) 80 80
Traction Enhancement Capacity 0.6 Coefficient of Friction 0.4 0.2 Dry Disk ALLEVIATE against wet leaf sample Wet leaf sample only 0.0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Cycles GM/GN2643 Guidance on Wheel/Rail Low Adhesion Simulation 81
GO Transit Union Station 0.6 Coefficient of Friction 0.5 COF avg = 0.45 8 COF avg = 0.36 9 0.4 Coefficient of Friction 0.3 0.2 COF avg = 0.30 6 COF avg = 0.31 0 0.1 0.0 Initial conditions (wet leaves on rail) After initial brake test (no ALLEVIATE ) After ALLEVIATE applied to rails After brake test with ALLEVIATE applied Before dry braking 1 Before dry braking 2 After 4 train passes After Gel applied 82 82
GO Transit Service Braking Test (40MPH) 800 700 600 Braking Distance [ft] 500 400 300 Baseline (Dry) ALLEVIATE 200 100 0 Trial 1 Trial 2 Trial 3 83 83
Summary of Friction Management Benefits on Transit Systems For curve noise at > 80 db (LAeq), 5 to 10 db reduction } New York, New Jersey, Sacramento, Los Angeles, Reduced corrugation growth rate } Extends grinding interval by at least double } In some cases, corrugations never return } Japan, Spain, Hong Kong, Italy, UK, Canada 30% reduction in vertical rail wear and 50% reduction in gauge face wear in sharp radius curves (PAT, RFI) Extend wheel life by 1.5 to 20X Increased traction Others } Vibration } Acoustic roughness 84